He had until tomorrow to either sign the bill into law or refer it to the Supreme Court to assess its constitutionality.

Tánaiste Eamon Gilmore said the decision is a key milestone in Irish Law.

He said: "The enactment of this legislation, 21 years after the Supreme Court ruling on the X Case, is a historic moment, particularly for the women of Ireland.

"The core purpose of this legislation is about saving women's lives. It is about providing for a very basic human right."

The Pro Life Campaign has said the passage "is a very sad day for our country" and "for the first time in our history makes it legal to deliberately target the life of an innocent human being".

Caroline Simons said: "Despite what the Taoiseach and others claim, the new law is life-ending not life-saving.

"The Government brought forward this law in the full knowledge that abortion is not a treatment for suicidal feelings and ignored all the peer reviewed evidence showing that abortion has adverse mental health consequences for women."